Sound transmitter for phonographs



Sept, 22, 1925.

G. K MILLS SOUND TRANSMITTER FOR PHONOGRAPHS Filed Dec. 51, 1919 2 Sheets-Sheet 1 Sept. 22, 1925. 1,554,455

G. K. MILLS SOUND TRANSMITTER FOR PHONOGRAPHS Filed Dec- 31, 1919 2 Sheets-Sheet 2 Patented Sept. 22, 1925.

UNITED STATES GREGG K. MILLS, or CHICAGO, ILLINOIS.

soUNn TRANSMITTER Fora rHoNoGRArHs.

Application filed December 31, 1919; Serial No. 348,681. i

elimination of vibrant connection between the body of the transmitter sound box that is supported upon the tone arm and a mountingthatis in supporting relation to the diaphragm, and is preferably also the mountingfor the stylus carrier, whereby not only vibrations imparted to the stylus bar or I other'stylus carrier, but vibrations imparted to the diaphragm also, are prevented from finding their way to the body of the transmitter box and the tone arm upon which the transmitter box body may be directly mounted.

In the preferred embodiment of myinvention, I embrace the diaphragm, the stylus bar and a mounting for these elements in a unitary structure detachably applicable to the box body with sound insulation between where this mounting a this mounting and the box body for the purpose stated. I do not wish to be limited to this construction however, as I consider it to be within the scope of my invention to employ the insulated mounting in supporting relation to the dia hragm, particularly l so supports the stylus carrier, whether such mounting forms an element of a unitary structure with the diaphragm and stylus carrier or not.

I will explain my invention more fully by reference to the accompanying drawings illustrating preferred embodiments thereof and in which Fig. 1 is a front view, with parts broken away, of a transmitter made in accordance with the preferred embodiment of the invention; Fig. 2 is a sectional view on line 22 of Fig. 1; Fig. 3 isa perspective view of th preferred mounting for the diaphragm; Fig. 4 is an enlarged sectional view of a part of the structure as it is illustrated in Fig. 2; Fig. 5 is a front View, with parts broken away, of another form of the invention; Fig. 6 is a sectional view on line 66 of Fig. 5; Fig. 7 is a perspective view of the mounting of Figs. 5 and'6 that is in supporting relation to the diaphragm and which supports the stylus carrier; and Fig. 8 is an 1,554,455 PATENT, OFFICE.

enlarged sectional view of a part o fthe modified structure as-it appears in Fig. 5.

Like parts are indicated by similar characters of reference throughout the airm n Referring first more particularly. to the structure illustrated in Figs. 1 toft inclusive,

'I have there illustrated a metallic tone arm portion 1 upon which is mounted the metallic body 2 of the sound box of a'transmitter.

This box body has an annular'channel 3 its front face. An annular body or cushion 4: of sound insulating material, such as rubber, is receivedin the channel 3to be flush with the front face of the box body. [This annular body of soundinsulating material itself has an annular channel 5 in which is received the flanged base 6 ofa metallic mounting ring 7, said base prO ec'tiIig beyond and within said ring to form outer and inner annular ledges.

structure that includes the sound transmitting diaphragm Sand the metallic stylus bar 8 in connection, at one end, with the In the structure shown in Figs. 1 to 4 inclusive the metallic mounting l, ring is a. component elementof a unitary central portion of the diaphragm. The dia-" phragm is supported by the ledge formed by the inner portion of the ringfbaseti,

there being a sound insulating cushio-nfi, between'the peripheral portion of the rear face of the diaphragm and this ledge- An-' other sound insulating cushion 10 is interposed between the peripheral portion of the front face of the diaphragm-and a metallic clamping ring 11 which is secured to the front of the mounting ring 7 by means of. screws 12. The sound insulating cushion gaskets 9 and 10 are preferably of tubular rubber, being sufiiciently collapsed by the ring 11 to give the diaphragm a substantially fixed position with respect to the sound box body, 2, without, however, making these gaskets s0 rigid as to be deprived of their cushioning and sound insulatingfunction. The metallic mounting ring 7 has a bifurcated exten sion between whose branches 13, 14 is pivoted the stylus bar 8. In accordancewith common practice, the stylus bar is provided with lateral trunnion extensions 15 recessed in their endsto receive the inner. ends of trunnion screws 16 secured in the bifurcation arms 13,14. The diaphragm and stylus bar being usually assembled before these elements areassembled in a unitary structure with the metal mounting ring 7 and metal clamping ceiving a stylus 19 that is held within said 7 ring 11, said clamping ring is the last of these elements to be placed in position, on-

which-account I form therein a radial slot 17 topermit the clamping ring to be passed over stylus bar. As is usual, the stylus-bar is also constituted a stylus carrier, having a socketed portion 18 at its lower end torresocket by a clamping screw 20.

Theunitary structure embracing mounting" ring 7 and parts carried thereby are, after the complete formation thereof,

assembled with the sound box body 2 by 8; an d is'clamped'between this ring base andthe clamping ring22 by means of clampingscrews23 passing through the clamping ringinto thesound'box body 2. There is thus provided a mounting for the stylus bar or other stylus canrienwhich also constitutes a mountlng for the diaphragm or 1s 1n supporting relationthereto, and sound insulation between this mounting and the sound box body to limit, as far as practicable, the

' direct transmission of sound vibrations from the record to'the diaphra m;

In Figs. 5 to 8 inclusive there is illustrated another form of the invention, similar parts inboth sets of figuresbeing given respectively similar characters of reference. In-

themodified structur the annular gasket 4; and the channel 5 within this gasket surround the entire metallic' ring 7, the gaskets 9: and 10, and the diaphragm 8, instead of beingin .a-plane parallel with these elements,

the latter: being the case with the structure of Figs. 1 to 4 inclusive. The peripheries of the gaskets 9 and 10 engage the inner face of the surrounding ring 7 '(Fig. 5) so that the ringv is in supporting. relation to. these gaskets and. the diaphragm 8 disposed between the gaskets. In the modified structure the r the metallic clamping ringll has an outer flange 24E clamped upon the boX- body by clamping screws 25. This clamping ring has an annular channel 26 constituting a continuation-"ofthe channel 3 in the boX body for receiving the sound insulating cushion 4. The inner wall- 27 of the channel 26 serves to clamp the gaskets 9 and 10 and the diaphragm 8'that is between these gaskets in assembly with the box body.

lVhile I have hereinshown and'particularly described preferred embodiments of my invention I do not wish to be limited to theprecise details of construct-ionshown as changes may readily be made without departing from the spirit of my inventionpbut having-thus described my invention-I cl'alm' as new and desire to secure by Letters Patent the following A sound transmitter comprising in com bination, a sound boX having a body portion for attachment. to a tone arm, said body portion being -disclike in form and provided with an annular channel near its periphery,

insulating material made in annular form and fitted into said channel, and in turn provided with an annular channel, a metallic ring fitted into said last mentioned channel, said ring being provided with outwardly pro ecting members-serving as supports for a sound transmitting elementysaid projections extending through said insulating material and also through said body portion, a diaphragm mounted in said ring, a sound transmitting element connected with the diaphragm and pivotally supported. by said projecting members, and a metallic clamping ringtfitted outside of said insulating material so asto hold the same and said mounting ring, in position and screws holding said clamping ring attached to said' body. por-tionJ Inwitness whereof, I hereunto subscribe my name this 22nd day of November A. 1)., 1919.

cases MILLS. 

